The effect of orthographic neighbourhood size (N) on lexical decision reaction time differs when words are presented in the left or right visual fields. Evidence suggests a facilitatory N effect (i.e., faster reaction times for words with larger neighbourhoods) in the left visual field. However, the N effect in the right visual field remains controversial: it may have a weaker facilitative role or it may even be inhibitory. In a pre-registered online experiment, we replicated the interaction between N and visual field and provided support for an inhibitory N effect in the right visual field. We subsequently conducted a pre-registered systematic review and meta-analysis to synthesise the available evidence and determine the direction of N effects across visual fields. Based on the evidence, it would seem the effect is inhibitory in the right visual field. Furthermore, the size of the N effect is considerably smaller in the right visual field. Both studies revealed considerable heterogeneity between participants and studies, and we consider the implications of this for future work.

The mean inter-tap interval (ITI) and the coefficient of variation of the ITI (ITIVAR) were measured in all five fingers of the preferred and non-preferred hand in two experiments. Subjects were right- or left-handed, males or females in experiments I and right-handed female typists, pianists, or controls in experiment II. Lack of consistent difference between right- and left-handers, and between those with and without special manual skills, suggested that hand differences in tapping are not a consequence of differential practise between hands. ITI showed differences both between fingers and between hands, whereas ITIVAR only showed differences between fingers. Separate mechanisms are inferred, and it is suggested that differences between fingers are a function of differential peripheral motor control, whereas differences between hands are a consequence of cerebral dominance of control mechanisms, and a model is presented.

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